#请在...补充一行或多行代码
#CalStatisticsV1.py
def getNum():       #获取用户不定长度的输入
    s=input()
    return list(eval(s))

def mean(numbers):  #计算平均值
    n=len(numbers)
    sum=0
    for i in numbers:
        sum+=i
    return sum/n
    
def dev(numbers, mean): #计算标准差
    sdev = 0.0
    for num in numbers:
        sdev = sdev + (num - mean)**2
    return pow(sdev / (len(numbers)-1), 0.5)

def median(numbers):    #计算中位数
    numbers.sort()
    size = len(numbers)
    if size % 2 == 0:
        med = (numbers[size//2-1] + numbers[size//2])/2
    else:
        med = numbers[size//2]
    return med
    
#n =  getNum() #主体函数
n='1,3,6,9,2,5,1'
n=list(eval(n))
m =  mean(n)
print("平均值:{:.2f},标准差:{:.2f},中位数:{}".format(m, dev(n, m), median(n)))
